Chandrayaan 3 Successful Lift-Off: Understanding MKV/M4 Stages and Onboard Instruments, moon landing date

 

Introduction

Chandrayaan 3 (MKV/M4), India’s ambitious lunar exploration mission using launch vehicle MKV/M4 started after successful lift-off on July 14, 2023, this mission aims to build upon the success of its predecessor, Chandrayaan 2, and further expand our knowledge about Earth’s celestial neighbor. In this article, we will delve into the MKV 3 stages, the instruments aboard Chandrayaan 3, and its objectives. Furthermore, we will explore the anticipated timeline for the spacecraft to reach the moon after lift-off.

Table of Contents

1. Introduction to the LVM 3 Satellite Launch Vehicle
2. First Stage: Solid Strap-On Motors (S200)
3. Second Stage: Liquid Core Stage (L110)
4. Third Stage: Cryogenic Upper Stage (C25)
5. Integration and Deployment
6. Payload and Equipment Specifications
7. Anticipated moon landing date
8. Conclusion
9. FAQs                                                                                                                                                                           

 

1. Introduction to the LVM3 Satellite Launch Vehicle

The Geosynchronous Satellite Launch Vehicle Mk III, or LVM3, is a significant achievement by ISRO. Its primary purpose is to launch heavy payloads, with a capacity of up to 4000 kg, into Geosynchronous Transfer Orbit (GTO) in a cost-effective manner. With the LVM3, ISRO has achieved full self-reliance in launching heavier communication satellites.

2. First Stage: Solid Strap-On Motors (S200)

The first stage of the LVM3 consists of Solid Strap-On Motors (S200). These solid boosters are among the largest in the world, containing 204 tonnes of solid propellant. The S200 motors provide initial thrust during launch and burn for approximately 134 seconds. After this, they are jettisoned to allow the next stage to take over.

3. Second Stage: Liquid Core Stage (L110)

Following the S200 boosters, the LVM3 continues its ascent with the Liquid Core Stage (L110). This stage features a twin liquid engine configuration and carries 115 tonnes of liquid propellant. The L110 stage is ignited around 113 seconds into the flight, concurrently with the firing of the S200 stages. At 137 seconds, the S200 boosters separate, and around 217 seconds, the payload fairing is jettisoned at an altitude of 115 km.

4. Third Stage: Cryogenic Upper Stage (C25)

The third and final stage of the LVM3 is the Cryogenic Upper Stage (C25). Equipped with a fully indigenous high-thrust cryogenic engine (CE20), the C25 stage carries 28 tons of propellant. Once the L110 stage burns out and separates at approximately 313 seconds, the C25 stage ignites. Within a nominal time of 974 seconds from liftoff, the spacecraft is injected into a Geosynchronous Transfer Orbit (GTO).

5. Integration and Deployment

Before launch, the various stages of the LVM3 are meticulously integrated and tested to ensure their functionality. The spacecraft, Payload Adapter (PLA), and the Payload Fairing (PF) are encapsulated within the payload fairing, which has a diameter of 5 meters. Once all systems are in place, the LVM3 is ready for liftoff.

At the designated launch time, the LVM3 initiates its first stage, with the S200 boosters providing the necessary thrust. As the first stage burns out, it separates, and the L110 stage takes over. Finally, after the L110 stage completes its burn, the C25 stage ignites, propelling the spacecraft into GTO.

 6.Chandrayaan 3: Payload and Equipment Specifications                                                                       

Chandrayaan-3, comprising a homegrown Lander module (LM), Propulsion module (PM), and a Rover, aims to develop and demonstrate cutting-edge technologies necessary for interplanetary missions. The LM possesses the capability to gently touch down at a predetermined lunar site and deploy the Rover, which will conduct on-site chemical analysis of the lunar surface as it moves around. Both the Lander and the Rover are equipped with scientific payloads to carry out experiments on the lunar terrain. The primary function of the PM is to transport the LM from the launch vehicle injection to the final lunar orbit of a circular polar nature, separating the LM from the PM in the process. Furthermore, the Propulsion Module includes an additional scientific payload as an added value, which will be operational after the separation of the Lander Module. The GSLV-Mk3 has been designated as the launcher for Chandrayaan-3, responsible for placing the integrated module in an Elliptic Parking Orbit (EPO) measuring approximately 170 x 36,500 km.

 

The mission objectives of Chandrayaan-3 are as follows:

 

Demonstrating a safe and soft landing on the lunar surface.

Demonstrating rover mobility on the moon.

Conducting in-situ scientific experiments.

To accomplish these objectives, the Lander incorporates various advanced technologies, including:

 

Altimeters: Laser-based and radio frequency (RF) altimeters.

Velocimeters: Laser Doppler Velocimeter and Lander Horizontal Velocity Camera.

Inertial Measurement: Inertial referencing and accelerometer package based on laser gyros.

Propulsion System: Throttleable liquid engines with a thrust of 800N, attitude thrusters with a thrust of 58N, and throttleable engine control electronics.

Navigation, Guidance & Control (NGC): Powered descent trajectory design and associated software elements.

Hazard Detection and Avoidance: Lander Hazard Detection & Avoidance Camera and processing algorithm.

Landing Leg Mechanism.

To demonstrate these advanced technologies under Earth conditions, several special tests have been planned and successfully carried out for the Lander:

 

Integrated Cold Test: Demonstrating the performance of integrated sensors and navigation through tests conducted using a helicopter as a platform.

Integrated Hot Test: Demonstrating closed-loop performance using sensors, actuators, and NGC through tests conducted with a tower crane as a platform.

Lander Leg Mechanism Performance Test: Simulating different touchdown conditions on a lunar simulant test bed.

The overall specifications for Chandrayaan-3 are as follows:

 

Mission Life (Lander & Rover): Approximately one lunar day, equivalent to around 14 Earth days.

Landing Site (Prime): Latitude: 69.367621° S, Longitude: 32.348126° E, with dimensions of 4 km x 2.4 km.

Science Payloads:

Lander: Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere (RAMBHA), Chandra’s Surface Thermophysical Experiment (ChaSTE), Instrument for Lunar Seismic Activity (ILSA), Laser Retroreflector Array (LRA).

Rover: Alpha Particle X-ray Spectrometer (APXS), Laser Induced Breakdown Spectroscope (LIBS).

Propulsion Module: Spectro-polarimetry of Habitable Planet Earth (SHAPE).

Two-Module Configuration:

Propulsion Module: Carries the Lander from launch injection to lunar orbit.

Lander Module: Accommodates the Rover.

Mass:

Propulsion Module: 2148 kg.

Lander Module: 1752 kg, including a 26 kg Rover.

Total: 3900 kg.

Power Generation:

Propulsion Module: 758 W.

Lander Module: 738 W with bias.

Rover: 50 W.

Communication:

Propulsion Module: Communicates with IDSN.

Lander Module: Communicates with IDSN and Rover. Chandrayaan-2 Orbiter is also planned as a contingency link.

Rover: Communicates solely with the Lander.

Lander Sensors:

Laser Inertial Referencing and Accelerometer Package (LIRAP).

Ka-Band Altimeter (KaRA).

Lander Position Detection Camera (LPDC).

Lander Hazard Detection & Avoidance Camera (LHDAC).

Laser Altimeter (LASA).

Laser Doppler Velocimeter (LDV).

Lander Horizontal Velocity Camera (LHVC).

Micro Star Sensor.

Inclinometer & Touchdown Sensors.

Lander Actuators: Four reaction wheels (10 Nms & 0.1 Nm).

Lander Propulsion System: Bi-propellant propulsion system (MMH + MON3) with four 800 N throttleable engines and eight 58 N throttleable engines with engine control electronics.

Lander Mechanisms:

Lander leg.

Rover Ramp (Primary & Secondary).

Rover.

ILSA, RAMBHA & ChaSTE Payloads.

Umbilical Connector Protection Mechanism.

X-Band Antenna.

Lander Touchdown Specifications:

Vertical Velocity: ≤ 2 m/sec.

Horizontal Velocity: ≤ 0.5 m/sec.

Slope: ≤ 120°.

The scientific payloads planned for the Chandrayaan-3 Lander Module and Rover have the following objectives:

 

Lander Payloads:

 

Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere (RAMBHA) – Langmuir probe (LP): Measuring the density of near-surface plasma (ions and electrons) and monitoring its variations over time.

Chandra’s Surface Thermophysical Experiment (ChaSTE): Conducting measurements of the thermal properties of the lunar surface in the polar region.

Instrument for Lunar Seismic Activity (ILSA): Monitoring seismic activity around the landing site and studying the structure of the lunar crust and mantle.

Laser Retroreflector Array (LRA): Passive experiment aimed at understanding the dynamics of the Moon system.

Rover Payloads:

Laser Induced Breakdown Spectroscope (LIBS): Performing qualitative and quantitative elemental analysis to determine the chemical composition and infer mineralogical composition, thereby advancing our understanding of the lunar surface.

Alpha Particle X-ray Spectrometer (APXS): Determining the elemental composition (Mg, Al, Si, K, Ca, Ti, Fe) of lunar soil and rocks in the vicinity of the lunar landing site.

Propulsion Module Payload:

Spectro-polarimetry of Habitable Planet Earth (SHAPE): Enabling the discovery of smaller planets through reflected light, allowing us to explore various exoplanets with potential habitability or signs of life.

In conclusion, Chandrayaan-3’s payload and equipment specifications reflect the mission’s aim to demonstrate safe landing, rover mobility, and in-situ scientific experiments on the lunar surface. The payloads and equipment encompass a range of advanced technologies and instruments designed to achieve these objectives. Through the utilization of state-of-the-art altimeters, velocimeters, inertial measurement systems, and a reliable propulsion system, Chandrayaan-3 aims to navigate the lunar environment with precision and gather valuable data.

 

The Lander module, with its laser-based and RF altimeters, enables accurate altitude measurement, while the laser Doppler velocimeter and Lander Horizontal Velocity Camera provide crucial velocity information for safe and controlled maneuvers. The inclusion of laser gyros in the inertial measurement system ensures precise referencing and acceleration measurements.

Hazard detection and avoidance are key aspects of the mission, and the Lander module is equipped with a Hazard Detection & Avoidance Camera and advanced processing algorithms to identify potential dangers during descent and landing. The landing leg mechanism ensures a stable touchdown, while the Ka-Band Altimeter and Laser Altimeter contribute to precise altitude determination.

The scientific payloads carried by the Lander module include the Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere (RAMBHA), Chandra’s Surface Thermo physical Experiment (ChaSTE), Instrument for Lunar Seismic Activity (ILSA), and a Laser Retroreflector Array (LRA). These instruments enable the measurement of plasma density, thermal properties of the lunar surface, seismic activity, and facilitate laser ranging studies.

 

The Rover module, housed within the Lander, is equipped with the Alpha Particle X-ray Spectrometer (APXS) and Laser Induced Breakdown Spectroscope (LIBS). These instruments play a vital role in analyzing the elemental composition of lunar soil and rocks, providing insights into the geological makeup of the landing site.

 

Additionally, the Propulsion Module carries the Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload, which aims to make future discoveries of smaller planets possible by studying reflected light and exploring a variety of exoplanets that may exhibit conditions suitable for habitability or the presence of life.

 

Chandrayaan-3’s comprehensive payload and equipment specifications showcase the commitment to scientific exploration and technological advancement. By harnessing the capabilities of these cutting-edge instruments, the mission endeavors to unlock new insights about the Moon’s surface and contribute to our broader understanding of celestial bodies within our solar system.

7. Anticipated Moon landing date

The voyage of Chandrayaan-3 from Earth to the Moon entails an estimated duration of about a month, with the anticipated landing scheduled for the 23rd of August. Once it touches down on the lunar surface, the spacecraft will commence its operations, functioning for the duration of one lunar day, which equates to approximately 14 Earth days. This intriguing time frame allows for an extended period of exploration and data collection, enabling the mission to delve deeper into the mysteries of the Moon and unravel its secrets

8.Conclusion

Chandrayaan 3 represents India’s unwavering commitment to space exploration and scientific discovery. With its advanced instruments and ambitious objectives, this mission aims to expand our knowledge of the moon’s composition, geological history, and the presence of water and volatiles. By unlocking the secrets of our celestial neighbor, Chandrayaan 3 will contribute to humanity’s understanding of the moon and its significance in our solar system. Chandrayaan 3 will provide valuable data that contributes to our understanding of the moon’s formation and evolution. Moreover, it will enhance India’s technological capabilities and strengthen its position in the global space community. As we eagerly anticipate the lift-off of Chandrayaan 3, the mission holds the promise of unveiling new discoveries and opening doors to future space exploration endeavors.

9 FAQ’s

FAQs

1. What is the Geosynchronous Satellite Launch Vehicle Mk III?                                                              The Geosynchronous Satellite Launch Vehicle Mk III, or LVM3, is a three-stage launch vehicle developed by ISRO for launching heavy payloads into Geosynchronous Transfer Orbit (GTO).
2. What are the stages of the LVM3?                                                                                                                  The LVM3 consists of the Solid Strap-On Motors (S200), Liquid Core Stage (L110), and Cryogenic Upper Stage (C25).
3. How much propellant does the S200 stage carry?                                                                                      The S200 stage carries 204 tonnes of solid propellant.
4. What is the purpose of the Cryogenic Upper Stage (C25)?                                                                       The C25 stage, equipped with a high-thrust cryogenic engine, propels the spacecraft into a Geosynchronous Transfer Orbit (GTO).
5. How has the LVM3 impacted India’s space capabilities?                                                                         The successful deployment of LVM3 has granted ISRO full self-reliance in launching heavier communication satellites into GTO, significantly enhancing India’s space capabilities.

6. What instruments are on board Chandrayaan 3?**                                                                        Chandrayaan 3 is equipped with various instruments, including the Seismic Experiment for Interior Structure (SEIS), Langmuir Probe, Radio Anatomy of Moon Bound Hypersensitive Ionosphere and Atmosphere (RAMBHA), Laser-Induced Breakdown Spectroscopy (LIBS), Alpha Particle Induced X-ray Spectroscopy (APIXS), Imaging Spectrometer (ILS), and Chandrayaan Alpha-ray Spectrometer (CHAS).